U. WARWICK (UK) — After the terrorist attacks of September 11, 2001, many new, young U.S. voters favored the Republican Party, a shift that has persisted for years, according to a new study.

Researchers looked at whether the act of registering for a political party today can affect future politics by causing enduring support for that party. The results clearly show that the decision to register with a political party can have effects that last for years, perhaps for a lifetime.

“Our research shows that party strategists should focus on winning over voters when they are young,” says Sharun Mukand, a professor at the University of Warwick. “However our findings have important implications for the political arena and for public policies. Policies may persist simply because support for a party endures.

“In particular, if voters are unwilling to shift political allegiance in response to new, politically relevant information, then policies out of tune with changing times may live on.”

The researchers examined the political affiliations of a group of first-time voters in California who registered to vote when they became eligible at age 18. Because of slight differences in their birthdates, these voters registered just before and just after the terrorist attacks of 9/11.

The analysis showed that two basically identical groups of people take up markedly different political agendas. Voters with birthdays in September were more likely to register as Republicans than voters with birthdays in August—by more than two percentage points.

The political affiliation of these voters persisted through to the year 2008—with those born in September consistently remaining two percent more likely to be Republican. This was true even for those voters who moved and, thus, had to change their registration.

This research may explain why politically partisan realignments happen very slowly. When President Lyndon B. Johnson signed the Civil Rights act in 1964, he said that his Democratic Party had “lost the South for a generation.” In fact, the loss took a generation to take place. Clear, persistent support for the Republican Party among Southern whites only emerged in 1994.

The researchers note that 9/11 is not the only moment in the last decade of U.S. politics that had a significant impact on young voters.

“Consider the implications of our findings when applied to the 2008 U.S. election. In this election, according to Pew Research Center, two third of voters ages 18-29 voted for Obama in 2008,” says Ethan Kaplan, a professor at Stockholm University and the University of Maryland.

“This compares to 53 percent of the general population. Our analysis suggests that this gap between the Obama “youth voters” and the general population is remarkably persistent over several election cycles. Indeed, our calculations suggest that the 2008 youth vote gap will be a phenomenon affecting U.S. elections for decades to come.”